Implementation of Digital Radio Mondiale receiver — Part II

Analog shortwave radio on bands up to 30 MHz has typically been limited in applicability for long-distance broadcast applications requiring high signal fidelity. This is because of the vulnerability of analog modulation schemes to atmospheric dispersion; however, the Digital Radio Mondiale (DRM) standard, introduced in 2001, is a promising solution for shortwave radio. DRM provides various audio and data digital encoding methods that utilize current data compression and error-detection features. These characteristics are attractive for shortwave broadcasters, particularly those desiring to implement economical, reliable studio-to-transmitter links. This paper presents a DRM receiver design which implements these features in addition to possessing firmware scalability for a planned diversity implementation. Significant improvements to the DRM receiver design presented in a previous paper are discussed, and the receiver´s increased performance is evaluated, particularly with regards to signal-to-noise ratio. The paper concludes with a discussion of future work.